Positioning mechanism for searchlights



May 12, 1925. 1,537,770

T. HALL POSITIONING MECHANISM FOR SEARCHLIGHTS Filed Aug. 25, 1919 4 Sheets-Sheet 1 7 E 4- IIIHIJI I 6 9 v1; IN 5 lNVENTOR 771500005 /'/H LL Hi5 ATTORNEY May 12, 1925. 1,537,770

T. HALL POSITIONING MECHANISM FOR SEARCHLIGHTS Fil d Aug, 23, 1919 4 Sheets-Sheet 2 i 73 6.9 7 r 7 69 l I'IHIHHHHHHHH I l NVE NTO R THMUURE fi/ILL.

-H|S ATTORNEY May 12, 1925. 1,537,770

T. HALL POSITIONING MECHANISM FOR SEARCHLIGHTS Filed Aug. 23, 1919 4 Sheets-Sheet 5 INVENTOR 771EL7DUHE HALL c1 IJW S A TORNEY May 12, 1925. 1,537,770

T. HALL POSITIONING MECHANISM FOR SEARCHLIGHTS 1 Filed Aug. 23, 1919 871 Sheets-Sheet 4 INVENTOR 77/5L70L7HE fimL HIS ATTORNE Patented May 12, 1925.

UNITED STATES PATENT OFFICE.

* THEODORE HALL, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE SPERRY GYROSCOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

POSITIONING MECHANISM FOR SEARCHLIGHTS.

Application filed August, 23, 1919. Serial No. 319,383.

Toall'whomz'tma concern:

Be it known t at I, Tnnonona HALL, a

citizen of the United States of America, re-

siding at 455 th Street, Brooklyn, in the county of Kings and State of New York,

of this invention may best be emphasized by.

considerin its application to a searchlight, although it should be borne in mind that the invention is capable of other uses, such as the control of a gun or any other object.

Heretofore, in systems of the type above referred to, the range of speed of the control has been quite limited, especially at long ranges, and the control has not been reliable at long ranges. By means of the system which I have devised, a far greater range of speed, viz, from '1 to 100 in either direction and in both elevation and azimuth, is obtained and, furthermore, the control is reliable at all ran es up to 10,000 yards.

A further a vantage of my invention is in its simplicity, in that it has no complicated parts and utilizes direct current.

Referring to the drawings in which I have illustrated what I now consider to be the preferred form of my invention Fig. 1 is a front elevation, partly in section, of a Searchlight unit showing the manner in which the elevating and training mo- 7 tors operate.

Fig. 2 is a plan view of the receiving po tentiometers together with? rheostat for varying the voltage supplied to the elevating and training motors.

Fig. 3 isan enlarged View, partly in section, of one of the receiving potentiometers, together with one of the motor potentiometers.

Fig. 4 is a transverse section on line 4-4 of Fig. 3.

Fig. 5--is a plan view of the transmitting potentiometers.

Fig. 6 is a longitudinal section on line 66 of Fig. 5.

Fig. 7 is a diagrammatic view of the wiring of my invention.

The searchlight 1 is mounted on trunnions 2, journalled in arms 3 secured to base 4 which is rotatably mounted on supporting platform 5. Ball bearings 6 may be provided between rotatable base 4 and platform 5. Said platform 5 also carries a motor 7 provided with a pinion 8 which meshes with annular gear 9 carried by the base 4, whereby the searchlight may be trainedin azimuth. A motor 14 (see Fig. 7) for actuating gearing 10, 11, 12, and thereby moving the Searchlight in elevation, may be placed in a bracket 13 secured to one of the arms 3. It is obvious, however, that the training and elevating motors may be connected to the searchlight in various ways, my invention not being limited to an particular type of connection between said motors and the Searchlight.

The motors 7 and 14 are energized by means of the system now to be described.

At the transmitting station are two transmitting potentiometers 15 and 16 provided with handles 17 and 18 respectively, secured to shafts 19' and 20, respectively. Shaft 19 is journalled in plates or partitions 21 .and

,22 and shaft 20 is journalled in plates or partitions 23 and 24. Partitions 21 and 22 are spaced apart by posts 25 and partitions 23 and 24 are spaced apart by posts 26. Spaced from partitions 22 and 24, respectively, are annular insulating members 27 and 28, respectively, each provided with a series of contacts 29 and 30 (see Fig. 7) respectively, each series of said contacts being preferably arranged on the arc of a circle as shown in Fig. 7 and provided with binding posts 29 and 30, respectively. Fixed at its center to shaft 19 is a contact arm 31, the end-portions of which are insulated from each other and carry contacts for engagement with contacts 29. Similarly shaft 20 is provided with a contact arm 32 for engagement with contacts 30. By way of example, I have illustrated three contacts on each side of the central or neutral position of the contact arm, as a result of which three speeds for each motor in either direction are provided. However, it is evident that any desired number of potentiometer contacts may be provided depending upon the number of speeds ineither direction desired.

Mounted on shaft '20 to turn therewith is an arm 33 provided with a pin 34. Attached to this pin at one end each are two springs 35 and 36, passing over pulleys 37 and 38, respectively, mounted on plate or wise has a partition 23, and said springs are attached at their other ends to hooks 39 projecting from block 40, mounted on partition 23. A plate 41 may be provided as a guard for said springs 35 and 36. Formed integral with arm 33, or otherwise suitably fixed to shaft 20, is an arm 42 provided with a springpressed plunger 43 carrying a roller 44 for engagement with a series of depressions 45 in an arc-shaped member 46. When handle 18, and hence shaft, 20, is turned in either direction, it will be seen that one or the other of the springs 35 and 36 will be placed under tension, whereby when said handle 18 is released the spring which has been placed under tension will return the handle to its central position. Plunger 43, roller 44, and depressions 45 are so located with respect to the series of contacts 30 that roller 44 engages one of said depressions only when contact'arm 32 rests squarely over contacts 30, each depression thus indicating that the arm 32 is centrally over a set of contact points. Handle 17 and shaft 19 are also provided with centralizing springs, potentiometers 15 and 16 being duplicates. Reference numerals 35, 40, and 46 in Fig. 5 designate elements corresponding to 35, 40, an 46, respectively. Both potentiometers 15 and 16 are preferably mounted on a suitable base 47, which base maycarry resistance or rheostat 48 and binding posts 49, both potentiometers being in circuit with said rheostat 48, as shown in Fig. 7.

At the receiving station are provided two receiving potentiometers 49 and 50, which are similar to the transmitting potentiometers. However, the respective contact arms 51 and 52 are each operated by a control motor. In Fig. 3 is shown potentiometer 49 having a control motor 53 mounted on the bottom of casing 54 and provided with a pinion 56 which meshes with gear 57, the hub 58 of which is toothed and meshes with gear 59. The latter gear liketoothed hub 60 which meshes with gear 61 loosely mounted above hub 58 on shaft 62 and provided with a toothed hub 63 meshing with gear 64 rigidly mounted on shaft 65. Shafts 62 and 65 are supported on plate or partition 66 which is supported in any suitable manner from the bottom of casing 54, as by means of posts 67. While, for purposes of illustration, I have disclosed a particular train of gears, it is obvious that the motor 53'may be connected in various ways to shaft 65 and the train of gears disclosed is to be taken as illustrative merelyand not in a limiting sense.

Supported from partition 66 b means of posts 67, or in any-other suita le manner, is a plate or partition 68 upon which are-secured by any suitable means, such as screw bolts 69, annular blocks 70 and 71 of insulating material. Block 70 is provided with a circular series of contacts 72 while block 71 is provided with a similar series of contacts 73. Contact arm 51 is rigidly mounted on shaft 65 for engagement with contacts 73, while preferably below contact arm 51 is a second contact arm 74, preferably mounted on shaft 65, for engagement with contacts 72. It will thus be seen that, when motor 53 is energized, both contact arms 51 and 74 will be turned with shaft- 65. Insulating members 70 and 71 may be spaced apart by any suitable means, as for instance by means of insulatin sleeves 75. To insure good cont-act the end of each contact arm may be provided with one or more spring-pressed plungers 76.-

The ends of each contact arm 51 and 74 are insulated from each other.

The ends of contact arm 74, which may be termed a motor contact arm, are connected to the armature of training motor 7, as shown in Fig. 7, while contacts 72 are connected to different portions of a rheostat 77. Likewise, a motor contact arm 78, preferably mounted below contact arm 52, has its ends in series with the armature of elevating motor 14 and engages with the contacts 79 likewise connected to various portions of rheostat 77. Contact arms 52 and 78 are moved b a motor 80, shown diagrammatically in ig. 7 and similar to motor 53. In fact, contact arms 52 and 78 and associated parts are duplicates of contact arms 51 and 74 and their associated parts.

From Fig. 7 it will be seen that as either motor contact arm 74 or 78 is rotated from one contact to the next the motor armature is connected across various portions of rheostat 77 and hence that various voltages are supplied to said armature. Since the fields 81 and 81 are directly connected to the main supply wires 82 and 83, which lead from any suitable source of current, as a battery or generator, it is evident that by varying the voltage of the current supplied to the armature of either motor 7 or 14 the speed of that motor may be varied accordingly. Furthermore, itwill be seen that the direction of rotation of the motor armature will depend upon the direction of rotation of the corresponding contact arm, since rotation of said contact arm in a clockwise direction will cause current to flow through said armature in one direction, while counterclockwise rotation of said .contact arm will result in a flow of current reserve "he speed of the motor increase more ly during the final steps of the rota ticn 01 he contact arm than during the first step of the rotation. In order to provide for varying the amount by which the motor speed is increased or diminished at each step of rotation ofthe contact arm 1 have provided rheostat 77 with a greater number of binding posts 8 1 than there are contacts '32 or 79 so that each of said contests may be connected to any one of several off said binding posts 8 1.

As is evident from Fig. 7, each of rheostats 48, 18, and 77 is connected across supply mains 82, 83 Rheostats 48 and 77 may obviously be located at any convenient place, but "tor purposes of illustration I have shown them mounted on the base 85 on which one receiving potentiometers 49 and 50 are mounted, said base being provided with suitable sets of binding posts 112, 118.

Since it is necessary to energize motors -53 in order for said motors to move contact arms '74: and 78, respectively, the

means whereby said motors are energized from the transmitting potentiometer arms 31 and 32, respectively, will now be described. As the means for energizing motor 80 is a duplicate of that for energizing motor 53, only the means for energizing the latter motor will be described in detail.

In series with said motor 53 is a centralized polarized relay consisting of an armature 86 pivoted at its center 11 1 over polarizing coil 87, which is continuously energised in any suitable way, as by means of a tap from rheostat 77, as shown in Fig. 7.. Two coils 88 and 89 are located under opposite ends of armature 86. Coil 88 is connected by wire 90 with one end of transmitting potentiometer contact arm 31 and by wire 91 with one end of receiving potentiometer contact arm 51, while coil 89 is connected by wire 92 with the other end of contact arm 31 and by wire 93 with the other end of contact arm 51. Consequently each coil 88 and 89 is in series with part of the sections or units of resistances or rheostats 18 and 4:8. The armature 86 is centralized and it is evident that any suitable springs or other means may be employed toward this end. I have shown at 91 a leaf spring hearing at the portion about its center on armature 86 and having its ends upturned and engaged by screws 95 carried by arms 96 secured to the base 85.

In the position of contact arms 31 and 51 shown in Fig. 7 it will be seen thatno current will flow through either of coils 88 or 89, since each end of each of said coils is connected to the same amount of resistance between mains 82 and 83. Thus, as shown in Fig. 7, the ends of coil 88 are connected to three sections or units of resistance in rheostats .18 and 48 respectively, and the same is true of the ends of coil 89, each section or unit of resistances 4:8 and 4:8 heing'olf equal resistance. In other words, the difierence of potential between the ends of each coil-is now zero and hence no cur rent will flow through either coil. Now, if arm 31 be moved through one step, say in a clockwise direction, until the ends of said arm engage the next set or contacts beyond the neutral position, the ends of each coil 88 and 89 will no longer be. connected through the same amount or resistance between the mains and current will flow from point 97 on main 82, assuming 82 to be the positive main, through two sections of rheostat 48 into wire 90, through coil 88, wire 91, the center one or contacts 73 on the right hand side of potentiometer 51, thence to the contact 73 diametrically opposite to the last named contact, through wire 98, coil 89, wire 92, the fourth contact 29 on the right hand side of potentiometer 15, through two sections of rheostat 48 to point 99 on main 83. Resistances 100 are inserted between each receiving potentiometer and the main line to compensate for the line drop between the receiver and transmitter.

When current flows through coils 88 and 89 as above set forth, the armature 88 of the polarized relay will be tilted in one direction or the other to contact with one of contacts 101, 102, thereby causing current to flow in one direction or the other through the armature or motor 53. Thus, it contact 102 be engaged by the relay armature 88, current will flow from main 82, through wire 103, wire 1041, contact 102 and armature 86, wire 105, the armature or" motor 53, wire 106, to point 107 on rheostat 77, and thence to the return main 83. ()n the other hand, if contact 101 be engaged by relay'armature 86, current will flow from main 82, through the first three sections 01 rheostat 77, wire 106, the armature of motor 53, wire 105, relay armature 86, contact 101, and wire 108 to return main 83. Obviously the direc* tion of the current through the armature of motor 53 will depend upon the direction of the current through coils 88 and 89 of the polarized relay, and the direction of the latter current obviously depends upon the direction in which contact arm 31 is rotated. Since the fields 109 and 110 of motors 53 and 80, respectively, are constantly connected directly across the main supply wires 82 and 83, the direction of rotation of each motor armature is determi ed by the direction of flow of current in the motor armature, and hence by the direction of rotation of arm 31.

Motor 53 having been energized by the actuation of the polarized relay armature 88, as above described, shaft 65, together with contact arms 51 and 74 are turned through the connection between said motor and shaft. The wiring connections between the polarized relay and motor armature are such that when the contact arm 31 of the transmitting potentiometer is rotated in a given direction, the armature of motor 53 will rotate so as to turn shaft and contact arms 51 and 74 in the opposite direction.

Now, assuming that contact arm 31 has been turned clockwise through one step as above set forth, motor 53 will be energized and will turn contact arm 51 through one step counter-clockwise. In this position of arm 51 the right hand end of contact arm 51 will engage the fifth contact 73 from the bottom on the right hand side of rheostat 48, while the left hand end of contact arm 51 will engage the third contact 73 from the bottom on the left hand side of rheostat 48. Consequently no more current will flow through coils 88 and 89 since each end of each coil is connected to the same amount of resistance between mains 82 and 83. Now since current is no longer flowing through coils,88 and 89 relay armature 86 is immediately returned to its neutral position by means of its centralizing spring 94 and motor 53 comes to rest. Should the inertia of motor 53 cause it to continue rotating for an interval after the supply of current has been out 01f, arm 51 will be moved into contact with the next set of contacts 73, thereby causing current to flow in the reverse direction through motor 53, and returning contactarm 51 to the position where it causes motor 53 to be deener gized by deenergizing the polarized relay.

Contact arm 51 having been turned so as to neutralize the potential and stop the motor 53 if the transmitter handle 17 is now released it is returned by its centralizing springs 35, 36 to its original position. The ends of each coil 88, 89 are again connected to a different amount of resistance between mains 82 and 83 and current will hence flow through said coils. This current will, however, flow in a direction opposite to the flow of the current resulting from the turning of arm 31 clockwise since the end of wire 91 connected to arm 51 is now at a higher potential than the end of wire 90 connected to arm 31, and the end of wire 92 connected to arm 31 is now at a higher potential than the end of wire 93 connected to arm 51. The relay armature 86 is, therefore, energized to engage that one of contacts 101, 102 which will cause motor 53 to return arm 51 to its position shown in Fig. 7 where it will again neutralize the potential and stop the motor. Thus, each movement of the handle of the transmitting potentiometer results in a corresponding movement of the contact arm of the receiving potentiometer.

Since contact arm 74 is moved with arm 51, it is evident that when motor 53 moves arm 51 to some new position, arm 74 is carried to the same new position, and a certain voltage is applied to motor 7 in a certain direction. Said motor 7 continues to operate at this voltage and speed until the transmitting potentiometer handle 17 is moved to some other position, whereupon arm 74 is carried to a corresponding position whereby a different voltage is impressed upon motor 7. Finally, when handle 17 is returned to its central position, shown in Fig. '7, thus causing the polarized relay to energize the control motor 53, contact arm 74 is returned to its original position and stops motor 7. In this position of contact arm 74 it should be noted that the armature of motor 7 is short-circuited, so that should the searchlight continue to rotate, motor 7 willnow be operated as a generator and due to its armature being short-circuited will exert a strong braking torque on the searchlight which will quickly bring the Searchlight to rest.

While I have described in detail the control of training motor 7 only, it will be evident from an inspection of Fig. 7 that the control of elevating motor 14 is identical with that of said training motor, the elements used in controlling the elevating and training motors being duplicates. In Figs. 2 and 7 I have designated corresponding parts of the corresponding polarized relays by the same reference characters, one set of which is primed.

If desired, suitable stops 111 may be provided for motor contact arm 74 and similar stops may be provided for the other contact arms.

While I have illustrated the motor contact arm 74 on the same shaft as contact arm 51 of the receiving potentiometer, various means for mounting contact arm 74 may obviously be employed, since it is merely necessary that contact arm 74 move through a certain distance when transmitting potentiometer handle 17 is moved through a given distance, and the same is true regarding motor contact arm 78.

Furthermore, while I have disclosed a specific set of control units for each of the Searchlight motors, it will be apparent to those skilled in the art that various typesof control units may be employed in the control system which I have devised, and the particular units which I have disclosed are to be regarded as merely illustrative of a convenient means of carrying out my invention and not as a limitation thereof. Also while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without interfering with the more general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. In combination, a plurality of rheostats, a common source of E. M. F. therefor, each rheostat having a movable contact arm, contacts on the ends of each contact arm, a polarized relay, including two coils, one end of each coil being electrically connected to the ends of one of said contact arms, the other end of each coil being electrically connected to the ends of the other of said contact arms, and a motor controlled by said polarized relay and mechanically connected to one of said movable contact arms.

2. In combination, a plurality of rheostats, a common source of E. M. F. therefor,

each rheostat having a movable contact arm, contacts on the ends of each contact arm, each rheostat also being electrically connected to a series of oppositely arranged contacts, the opposite ends of each contact arm being adapted to engage with the corresponding oppositely arranged contacts, a polarized relay, including two coils, one end of each coil being electrically connected to the ends of one of said contact arms, the other end of each coil being electrically connected :to the ends of the other of said contact arms, and a motor controlled by said polarized relay and mechanically connected to one of said movable contact arms.

In testimony whereof I have afiixed my signature.

THEODORE HALL. 

